High-ish velocity and brass life

[Tackdriver VillenTactical]

Long story short, I am pushing about 2650- 2700 FPS (slightly less, recently as the air temps are cooling) out of a 16” 223 AR barrel with 77gr match kings. I recently read that this is fast for a 16” barrel and that brass life will be shortened to only a few reloads.

Is this true? So far I’m on my 6th reloads with this brass without any issues. Also, why would the barrel length matter for brass life? Would I get more out of the brass if it were 20”?

Dave

 

[Mike 53]

Can I ask where you read that?

 

[paul73]

Long story short, I am pushing about 2650- 2700 FPS (slightly less, recently as the air temps are cooling) out of a 16” 223 AR barrel with 77gr match kings. I recently read that this is fast for a 16” barrel and that brass life will be shortened to only a few reloads.

Is this true? So far I’m on my 6th reloads with this brass without any issues. Also, why would the barrel length matter for brass life? Would I get more out of the brass if it were 20”?

Dave

2750-ish something is the sweet spot accuracy wise, i would think. if brass shows no bolt marks or other pressure stress signs - why to bother?

 

[Tackdriver VillenTactical]

Can I ask where you read that?

I don’t recall, I’ll see if I can find it tonight. However it was from a site where I find most people are knowledgeable about what they write. (Like Accurate shooter, 6mmbr, etc.). And it seemed to be a sentiment agreed upon by many on that board.

Maybe in benchrest guns it matters. I’m at a loss as I’ve never experienced it.

Dave

 

[mac1911]

Can I ask where you read that?

I don’t recall, I’ll see if I can find it tonight. However it was from a site where I find most people are knowledgeable about what they write. (Like Accurate shooter, 6mmbr, etc.). And it seemed to be a sentiment agreed upon by many on that board.

Maybe in benchrest guns it matters. I’m at a loss as I’ve never experienced it.

Dave

Are you sure they where talking about 223?
Unless you have a “loose” chamber and are resizing your brass excessively?

 

[northny]

The brass life is related to cartridge pressure not barrel length, but…….

The same cartridge in a longer barrel will usually give a higher muzzle velocity than in shorter barrel (generally 100 FPS more per inch) so….

So to get to the same FPS in a 16” barrel as in a 20” barrel the cartridge in the shorter barrel has to be loader hotter, so the cartridge in the 16” barrel has more pressure and may have shorter brass life.

Generally speaking of course

 

[jasons]

High pressures do stress brass more but what you’re talking about isn’t excessive in my experience. I shot a lot of 77 SMKs pretty much as fast as I could get them to go. I noticed that if the brass survived the first 2 or 3 loads it would usually last 8 or 9. Generally I’d start seeing the primer pockets get loose before I saw “the ring” or had case head separations or split necks (I mostly used lake city.) I liked using brass on it’s 4th or 5th load for real matches because by then if it was going to fail it probably would have but the primer pockets were still tight.

I also ran pretty tight chambers and was careful resizing. If you run a looser chamber you might not get the same longevity.

Gas system length may play a factor too. A carbine gas system on a 16” barrel makes for a pretty violent pressure spike that would probably beat up the brass more than a mid-lenth gas system might.